Connections between endoplasmic reticulum stress-associated unfolded protein response, mitochondria, and autophagy in arsenic-induced carcinogenesis

Crosstalk between autophagy and other forms of programmed cell death

Cell death occurs continuously throughout individual development. By removing damaged or senescent cells, cell death not only facilitates morphogenesis during the developmental process, but also contributes to maintaining homeostasis after birth. In addition, cell death reduces the spread of pathogens by eliminating infected cells. Cell death is categorized into two main forms: necrosis and programmed cell death. Programmed cell death encompasses several types, including autophagy, pyroptosis, apoptosis, necroptosis, ferroptosis, and PANoptosis. Autophagy, a mechanism of cell death that maintains cellular equilibrium via the breakdown and reutilization of proteins and organelles, is implicated in regulating almost all forms of cell death in pathological contexts. Notably, necroptosis, ferroptosis, and PANoptosis are directly classified as autophagy-mediated cell death. Therefore, regulating autophagy presents a therapeutic approach for treating diseases such as inflammation and tumors that arise from abnormalities in other forms of programmed cell death. This review focuses on the crosstalk between autophagy and other programmed cell death modalities, providing new perspectives for clinical interventions in inflammatory and neoplastic diseases.

TRAF3IP3 Induces ER Stress-Mediated Apoptosis with Protective Autophagy to Inhibit Lung Adenocarcinoma Proliferation

TNF receptor-associated factor 3 interacting protein 3 (TRAF3IP3/T3JAM) exhibits dual roles in cancer progression. While upregulated in most malignancies and critical for immune regulation. However, the specific effects and molecular mechanisms of TRAF3IP3 on the progression of lung adenocarcinoma (LUAD) remains poorly understood. This study reveals TRAF3IP3 is upregulated in several tumor tissues but exclusively decreased in LUAD and Lung squamous cell carcinoma (LUSC) tissues, consequential in a favorable overall survival (OS) in LUAD rather than LUSC. Herein, it is reported that TRAF3IP3 can suppress cell proliferation and promote the apoptosis rate of LUAD cells by inducing excessive ER stress-related apoptosis. Importantly, TRAF3IP3 triggers ER stress via the PERK/ATF4/CHOP pathway, accompanied by stimulated ER stress-induced cytoprotective autophagy in LUAD cells. Through IP-MS analysis, STRN3 is identified as a direct downstream interactor with TRAF3IP3 and corroborated to regulate ER stress positively. Mechanistically, TRAF3IP3 facilitates the recruitment of STRN3 to the ER lumen through its transmembrane domain and fulfills its functional role in ER stress in an STRN3-dependent manner in LUAD cells. Given its dual role in orchestrating ER stress-associated apoptosis and autophagy in LUAD cell fate determination, the importance of TRAF3IP3 is highlighted as novel therapeutic target for LUAD treatment.

SRP19 and the protein secretion machinery is a targetable vulnerability in cancers with APC loss

Loss of the tumor suppressor gene (TSG) Adenomatous Polyposis Coli (APC) is a hallmark event in colorectal cancers. Since it is not possible to directly target a TSG, no treatment options are available for these patients. Here, we identify SRP19 and the protein secretion machinery as a unique vulnerability in cancers with heterozygous APC loss. SRP19 is located 15 kb from APC and is almost always codeleted in these tumors. Heterozygous APC/SRP19 loss leads to lower levels of SRP19 mRNA and protein. Consequently, cells with APC/SRP19 loss are vulnerable to partial suppression of SRP19. Moreover, we show that SRP19 is rate limiting for the formation of the Signal Recognition Particle, a complex that mediates ER-protein translocation, and thus, heterozygous SRP19 loss leads to less protein secretion and higher levels of ER-stress. As a result, low-dose arsenic trioxide induces ER-stress and inhibits proliferation in cultured cell lines and animal models. Our work identifies a strategy to treat cancers with APC deletion and provides a framework for identifying and translating vulnerabilities associated with loss of a TSG.

Sigma-1 Receptor Specific Biological Functions, Protective Role, and Therapeutic Potential in Cardiovascular Diseases

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide, and there is an urgent need for efficient and cost-effective treatments to decrease the risk of CVD. The sigma-1 receptor (S1R) plays a role in the development of cardiac hypertrophy, heart failure, ventricular remodeling, and various other cardiac diseases. Preclinical studies have shown that S1R activation has considerable beneficial effects on the cardiovascular system, and this knowledge might contribute to informing clinical trials associated with the prevention and treatment of CVDs. Therefore, the objective of this review was to investigate the mechanisms of S1R in CVD and how modulation of pathways contributes to cardiovascular protection to facilitate the development of new therapeutic agents targeting the cardiovascular system.

An integrated machine learning framework for developing and validating a prognostic risk model of gastric cancer based on endoplasmic reticulum stress-associated genes

Background

Gastric cancer (GC), a prevalent and deadly malignancy, demonstrates poor survival outcomes. Evidence has emerged indicating that disruptions in endoplasmic reticulum homeostasis are significantly implicated in the onset and progression of various oncological conditions. This study was designed to construct a prognostic model based on genes related to endoplasmic reticulum stress(ERS) to predict survival outcomes in patients with GC.

Methods

Expression profiling data for GC samples were extracted and analyzed from TCGA-STAD, revealing 214 genes related to endoplasmic reticulum stress that show differential expression when compared with normal gastric tissue. Building on these insights, a prognostic model was formulated using data from TCGA-STAD and validated through subsequent analyses of GEO datasets. The tumor immune dysfunction and exclusion(TIDE) algorithm was applied to determine the susceptibility of individuals in high- and low-risk categories to immunotherapy. The presence of immune and stromal cells within the tumor microenvironment was assessed with the aid of the ESTIMATE algorithm. Sensitivity variations to prevalent anticancer drugs between the risk groups were evaluated using the Genomics of Drug Sensitivity in Cancer(GDSC) database, and prospective therapeutic agents were confirmed through molecular docking techniques.

Results

Thirty-one endoplasmic reticulum stress (ERS)-related differentially expressed genes (DEGs) crucial for prognosis in GC were pinpointed. These DEGs were then used to construct a prognostic model and were considered as independent prognostic factors for GC patients. This risk model proved to have a good predictive performance for estimating the overall survival of these patients. The patients placed into the high-risk group showed worse results and lower sensitivity to immunotherapy. Moreover, five specific targeted therapy drugs, namely BMS-754807, Dasatinib, JQ1, AZD8055 and SB505124, produced better results in the treatment of the high-risk group of patients.

Conclusions

A new molecular prognostic model associated with ERS was established and validated for GC and showed relatively good discriminative and predictive ability. This model greatly expands the collection of weapons in the armoury of prognostic analysis in GC.

Molecular disturbances and thyroid gland dysfunction in rats chronically exposed to a high dose of NaAsO₂: Insights from proteomic and phosphoproteomic analyses

Arsenic is a ubiquitous hazardous metalloid that poses a significant threat to human health. Although researchers have investigated the detrimental effects of arsenic on the thyroid, a comprehensive exploration of its toxicological impact and underlying molecular mechanisms remains to be conducted. Both this study and our previous reports demonstrated that chronic exposure to sodium arsenite (NaAsO2) results in histological impairment and dysfunction of the thyroid glands in Sprague-Dawley (SD) rats. Proteomic and phosphoproteomic analyses were performed to investigate the molecular mechanisms underlying the effects of chronic NaAsO2 exposure on thyroid function in SD rats. NaAsO2 disrupts the synthesis of thyroid hormones (THs) and alters the expression of the THs-synthesizing enzyme dual oxidase 2. In addition, oxidative phosphorylation, the AMP-activated protein kinase signaling pathway, central carbon metabolism in cancer, cysteine and methionine metabolism, cellular response to heat stress, and protein processing in the endoplasmic reticulum were upregulated, whereas glutathione metabolism was downregulated. In conclusion, this study revealed thyroid damage in SD rats induced by chronic NaAsO2 exposure and elucidated the disrupted molecular pathways, thereby providing novel insights into the molecular mechanisms underlying arsenic exposure and its impact on thyroid function.

FAM134B-mediated endoplasmic reticulum autophagy protects against cisplatin-induced spiral ganglion neuron damage

Introduction

Cochlear spiral ganglion neurons (SGNs) could be damaged by ototoxic drug, cisplatin (Cis), during which process autophagy was involved. FAM134B, the first detected endoplasmic reticulum autophagy (ER-phagy) receptor, plays an important part in the dynamic remodelling of the ER, the mutation of which affects sensory and autonomic neurons. However whether FAM134B-mediated ER-phagy involved in Cis-induced SGN damage or not was unknown. The present study was designed to determine whether FAM134B is expressed in SGNs of C57BL/6 mice and, if so, to explore the potential function of FAM134B in Cis-induced SGN damage in vitro.

Methods

Middle turns of neonatal murine cochleae were cultured and treated with 30 μM Cis in vitro. The distribution of FAM134B, morphological changes of SGNs, and the colocalization of ER segments with lysosomes were measured by immunofluorescence (IF). Apoptosis was measured by TUNEL staining. The expression of FAM134B, proteins associated with ER stress, autophagy and apoptosis was measured by western blot. The reactive oxygen specie (ROS) levels were evaluated by MitoSOX Red and 2',7'-Dchlorodihydrofluorescein diacetate (DCFH-DA) probe. Anc80-Fam134b shRNA was used to knockdown the expression of FAM134B in SGNs.

Results

We first found the expression of FAM134B in the cytoplasm of SGNs, especially in the fourth postnatal day mice. Results showed decreases in the number of SGNs and FAM134B expression, as well as increases of ROS level, ER stress, ER-phagy, and apoptosis after Cis stimulus. Inhibiting autophagy increased the expression of FAM134B, and aggravated Cis-induced SGN damage, while the opposite changes were observed when autophagy was activated. Additionally, co-treatment with the N-Acetyl-L-Cysteine (NAC), ROS scavenger, alleviated Cis-induced ER stress, ER-phagy, and apoptosis. What's more, knockdown the expression of FAM134B in SGNs made SGNs more vulnerable to cisplatin-induced injury.

Discussion

The present study revealed the expression pattern of FAM134B in C57BL/6 murine SGNs for the first time. Moreover, our work further verified the protective function of FAM134B mediated by ER-phagy in Cis-induced SGN apoptosis, at least partially, correlated with the accumulation of ROS and induction of ER stress, though the detailed regulatory mechanism through which needs much more work to reveal.

Chronic NaAsO2 exposure promotes migration and invasion of prostate cancer cells by Akt/GSK-3β/β-catenin/TCF4 axis-mediated epithelial-mesenchymal transition

Inorganic arsenic is a Class I human Carcinogen. However, the role of chronic inorganic arsenic exposure on prostate cancer metastasis still unclear. This study aimed to investigate the effects and mechanism of chronic NaAsO2 exposure on migration and invasion of prostate cancer cells. DU145 and PC-3 cells were exposed to NaAsO2 (2 μM) for 25 generations. Wound healing and Transwell assays showed that chronic NaAsO2 exposure promoted migration and invasion of DU145 and PC-3 cells. In addition, chronic NaAsO2 exposure induced epithelial-mesenchymal transition (EMT) of DU145 cells by promoting β-catenin/TCF4 transcriptional activity. Mechanically, NaAsO2 promoted GSK-3β inactivation in the "disruption complex" through Akt- mediated phosphorylation at serine 9, and then inhibited the phosphorylation and ubiquitination degradation of β-catenin, which led to its nuclear translocation. Ly294002, a selective phosphatidylinositol 3-kinase (PI3K)/Akt inhibitor, suppressed the β-catenin/TCF4 complex activation and EMT through blocking Akt-mediated GSK-3β inactivation in the "disruption complex" in chronic NaAsO2 exposed DU145 and PC-3 cells. Moreover, Ly294002 alleviated chronic NaAsO2-induced migration and invasion in DU145 and PC-3 cells. These findings provide evidence that chronic arsenic exposure promotes migration and invasion of prostate cancer cells via an EMT mechanism driven by the AKT/GSK-3β/β-catenin/TCF4 signaling axis. Akt is expected to be a potential therapeutic target for chronic arsenic exposure-mediated prostate cancer metastasis.

Inorganic arsenic modulates cell apoptosis by regulating Argonaute 2 expression via the p53 pathway

This study explores the role of Argonaute 2 (AGO2) in the induction of apoptosis by arsenic in 16HBE cells and investigates the association between AGO2 expression and arsenic exposure in a human population. By silencing AGO2 with siRNA, we examined its impact on cell viability and apoptosis using CCK-8, HO-PI, and JC-1 assays, complemented by qRT-PCR and Western blot analyses for gene and protein expressions. Our findings revealed a significant correlation between AGO2 expression and levels of exposure to inorganic arsenic (iAs), which was more pronounced than with other arsenic forms such as monomethylarsonic (MMA) and dimethylarsinic acids (DMA). The results showed that silencing AGO2 not only reduced cell viability but also intensified apoptosis, highlighting its role in activating the p53 pathway. This was further supported by increased phosphorylation of p53 at Ser392 and Thr55, reinforcing AGO2's involvement in apoptotic processes. The study underscores the potential of AGO2 as a therapeutic target in arsenic-related pathologies and highlights the critical need for managing occupational exposure to arsenic.

Abcb1 is involved in the efflux of trivalent inorganic arsenic from brain microvascular endothelial cells

Arsenic (As) can penetrate brain tissue through the blood-brain barrier (BBB), and the ATP-binding cassette subfamily B member 1 (Abcb1) has been shown to facilitate the transport of inorganic arsenic (iAs) in animal liver, small intestine, and yeast. However, the relationship between Abcb1 and BBB has not been reported, and the mechanism of brain microvascular endothelial cells Abcb1 on the transport of iAs needs to be further studied. Increased arsenic levels were observed in mice exposed to 25 mg/L or 50 mg/L of sodium arsenite (NaAsO2) in drinking water, and both arsenic uptake and efflux were detected in bEnd.3 cells treated with 16 μmol/L NaAsO2. Elevated levels of Abcb1 protein were found in the NaAsO2-exposed mouse brain microvascular endothelium and in NaAsO2-treated bEnd.3 cells. Inhibition of Abcb1's efflux function significantly reduced the 2-hour arsenic efflux rate in bEnd.3 cells loaded arsenic. Conversely, overexpression of either Abcb1a or Abcb1b significantly increased the 2-hour arsenic efflux rate in these cells loaded arsenic. These findings suggest that Abcb1 may play a crucial role in mediating arsenic efflux from mouse brain microvascular endothelial cells.

Insights into the protective effect of omega-3 nanoemulsion against colistin-induced nephrotoxicity in experimental rats: regulation of autophagy and necroptosis via AMPK/mTOR and RIPK1/RIPK3/MLKL signaling pathways

Colistin is considered one of the most effective antibiotics against gram-negative bacteria. However, nephrotoxicity is one of the dose-limiting factors in its treatment. This study aimed to evaluate the outcome of omega-3 nanoemulsion against colistin-induced nephrotoxicity and its possible underlying mechanism. Four rat groups were involved in the present research; each group containing ten rats was divided as follows: Group I (control) rats received normal saline; Group II (omega-3 nanoemulsion) rats received a dose of 500 mg/kg/body weight orally; Group III (colistin) rats received colistin intraperitoneally (300.000 IU/kg/day); and Group IV (colistin/omega-3 nanoemulsion) rats were treated for six days. The results revealed that colistin administration caused deterioration in renal functions such as creatinine, blood urea nitrogen, 24 h proteinuria, and kidney injury molecule-1 with decrease in creatinine clearance, resulting in histological alternation and tubular damage with diffuse interstitial inflammation. Additionally, colistin significantly increased the lipid peroxidation marker malonaldehyde, proinflammatory cytokines tumor necrosis alpha, interleukin-6, interleukin-1 beta. Also, autophagy influx marker microtubule-associated protein light chain 3B, Beclin-1, and necroptotic related proteins, receptor-interacting protein kinase-3 (RIPK-3), RIPK-1, mixed lineage kinase domain-like protein, and autophagy pathway regulatory kinase AMP-activated protein kinase, with a decrease in antioxidant enzymes catalase, superoxide dismutase, and total antioxidant capacity, autophagic marker ubiquitin-binding protein (p62), and regulator Mammalian target of rapamycin. Interestingly, omega-3 nanoemulsion reversed the results above, dramatically improving renal function and histological picture. Thus, omega-3 nanoemulsion provided a notable method for suppressing colistin-induced nephrotoxicity via its antioxidant and anti-inflammatory power, inhibiting pathological autophagy and necroptosis.

Enhanced endoplasmic reticulum stress signaling disrupts porcine sertoli cell function in response to Bisphenol A exposure

Bisphenol A (BPA), a pervasive substance in our daily lives and livestock excreta, poses significant threats due to its infiltration into foods and water sources. BPA has adverse impacts on male reproductive function, particularly affecting the critical Sertoli (ST) cells that play a pivotal role in the process of spermatogonia differentiating into spermatozoa. In this study, we examined the prevalence of BPA within the pig industry and delved into the impact of BPA exposure on the motility of boar sperm, the function of pig ST cells, as well as the underlying molecular mechanisms involved. This study revealed spatial disparities in the global distribution of BPA and its analogue contamination, utilizing data compiled from 130 comprehensive studies. The average concentration of BPA found in pig feed ranges from 9.7 to 47.9 μg/kg, while in serum, it averages between 55.1 and 75.6 ng/L. The BPA concentration in feed exhibits a negative correlation with sperm viability and the percentage of progressive motile spermatozoa. Exposure to BPA reduced sperm motility in boar and ST cell activity at both 6 and 24 h. The transcriptome analysis revealed that, compared to untreated control cells, endoplasmic reticulum stress (ERS)-related genes were upregulated in ST cells exposed to BPA at 6 and 24 h. This activation of ERS in ST cells was mediated by receptor protein kinase RNA-like endoplasmic reticulum kinase (PERK), inositol-requiring protein-1α (IRE1α), and activating transcription factor 6 (ATF6). Additionally, BPA exposure triggered oxidative stress and a proinflammatory response mediated by the transcription factor NF-κB, accompanied by an increase in downstream proinflammatory cytokines. BPA exposure also led to apoptosis in ST cells and upregulated the expression levels of pro-apoptosis proteins. However, inhibiting ERS activity with 4-PBA attenuated the BPA-induced inflammatory response and apoptosis in ST cells. Our findings suggest that BPA induced apoptosis and inflammatory response in porcine ST cells through persistent activation of ERS, thereby compromising the normal function of these cells.

Construction of an endoplasmic reticulum stress and cuproptosis -related lncRNAs signature in chemosensitivity in hepatocellular carcinoma by comprehensive bioinformatics analysis

Endoplasmic reticulum stress (ERS) and cuproptosis have remarkable effects on hepatocellular carcinoma (HCC) leading to a poor prognosis. The current study aimed to explore credible signature for predicting the prognosis of HCC based on ERS and cuproptosis-related lncRNAs. In our study, clinical and transcriptomic profiles of HCC patients were obtained from the Cancer Genome Atlas (TCGA) database. An ERS and cuproptosis-related lncRNA prognostic signature, including NRAV, SNHG3, LINC00839 and AC004687.1, was determined by correlation tests, Cox regression analysis, least absolute shrinkage, and selection operator (LASSO) methods. Survival and predictive value were evaluated using Kaplan-Meier and receiver operating characteristic (ROC) curves, while calibration and nomograms curves were developed. Besides the enrichment analyses for ERS and cuproptosis-related lncRNAs, mutational status and immune status were assessed with TMB and ESTIMATE. Additionally, consensus cluster analysis was employed to compare cancer subtype differences, while drug sensitivity and immunologic efficacy were evaluated for further exploration. qRT-PCR and CCK-8 were utilized to verify the alteration of the prognostic lncRNAs expression and proliferation in vitro. High-risk groups exhibited poorer prognosis. The signature exhibited robust predictive value as an independent prognostic indicator and showed significant correlation with clinicopathological features. In the enriched analysis, biological membrane pathways were enriched. Low-risk patients had lower TMB and higher immune status. A cluster analysis revealed that cluster 2 had the best clinical immunological efficacy and most active immune function. In brief, our constructed signature with ERS and cuproptosis-related lncRNAs was associated survival outcomes of HCC, and can be used to predict the clinical classification and curative effect.

Crystalline silica-induced endoplasmic reticulum stress promotes the pathogenesis of silicosis by augmenting proinflammatory interstitial pulmonary macrophages

Crystalline silica (CS) particles are ubiquitously present in the environment, particularly in occupational settings, and exposure to respirable CS causes silicosis, imposing a significant disease burden. However, the pathogenesis of silicosis remains unclear. Exposure to external stimuli, such as CS, leads to the accumulation of unfolded proteins and triggers endoplasmic reticulum (ER) stress, disrupting tissue immune homeostasis and accelerating pathological progression. While pulmonary macrophages phagocytose CS particles to initiate the immune response, the role of ER stress in this process is unknown. Herein, we used a murine model of silicosis to simulate the pathological progression from acute inflammation to fibrosis in silicosis and conducted in vivo pharmacological inhibition of ER stress to explore the underlying mechanism. Using flow cytometry, we further classified pulmonary macrophages into monocyte-like macrophages (monocytes), interstitial macrophages (IMs), and alveolar macrophages (AMs). Our results showed that CS-induced ER stress primarily contributed to the augmentation of IMs and thereby exerted a significant impact on pulmonary macrophages. Despite coexpressing M1- and M2-like markers, IMs predominantly exhibited an M1-like polarization state and played a proinflammatory role by expressing the cytokines pro-IL-1β and TNF-α during the pathological progression of silicosis. Additionally, IMs recruited by CS-induced ER stress also exhibited high expression of MHCII and exerted active immunomodulatory effects. Overall, our study demonstrates that ER stress induced by CS particles triggers a proinflammatory immune microenvironment dominated by IMs and reveals novel insights into the pulmonary toxicological effects of CS particles.

Hepatoprotective effects of zingerone on sodium arsenite-induced hepatotoxicity in rats: Modulating the levels of caspase-3/Bax/Bcl-2, NLRP3/NF-κB/TNF-α and ATF6/IRE1/PERK/GRP78 signaling pathways

OBJECTIVE

Long-term exposure to arsenic has been linked to several illnesses, including hypertension, diabetes, hepatic and renal diseases and cardiovascular malfunction. The aim of the current investigation was to determine whether zingerone (ZN) could shield rats against the hepatotoxicity that sodium arsenite (SA) causes.

METHODS

The following five groups of thirty-five male Sprague Dawley rats were created: I) Control; received normal saline, II) ZN; received ZN, III) SA; received SA, IV) SA + ZN 25; received 10 mg/kg body weight SA + 25 mg/kg body weight ZN, and V) SA + ZN 50; received 10 mg/kg body weight SA + 50 mg/kg body weight ZN. The experiment lasted 14 days, and the rats were sacrificed on the 15th day. While oxidative stress parameters were studied by spectrophotometric method, apoptosis, inflammation and endoplasmic reticulum stress parameters were measured by RT-PCR method.

RESULTS

The SA disrupted the histological architecture and integrity of the liver and enhanced oxidative damage by lowering antioxidant enzyme activity, such as those of glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), glutathione (GSH) level and increasing malondialdehyde (MDA) level in the liver tissue. Additionally, SA increased the mRNA transcript levels of Bcl2 associated x (Bax), caspases (-3, -6, -9), apoptotic protease-activating factor 1 (Apaf-1), p53, tumor necrosis factor-α (TNF-α), nuclear factor kappa B (NF-κB), interleukin-1β (IL-1β), interleukin-6 (IL-6), c-Jun NH2-terminal kinase (JNK), mitogen-activated protein kinase 14 (MAPK14), MAPK15, receptor for advanced glycation endproducts (RAGE) and nod-like receptor family pyrin domain-containing 3 (NLRP3) in the liver tissue. Also produced endoplasmic reticulum stress by raising the mRNA transcript levels of activating transcription factor 6 (ATF-6), protein kinase RNA-like ER kinase (PERK), inositol-requiring enzyme 1 (IRE1), and glucose-regulated protein 78 (GRP-78). These factors together led to inflammation, apoptosis, and endoplasmic reticulum stress. On the other hand, liver tissue treated with ZN at doses of 25 and 50 mg/kg showed significant improvement in oxidative stress, inflammation, apoptosis and endoplasmic reticulum stress.

CONCLUSIONS

Overall, the study's data suggest that administering ZN may be able to lessen the liver damage caused by SA toxicity.

GRP78/IRE1 and cGAS/STING pathway crosstalk through CHOP facilitates iodoacetic acid-mediated testosterone decline

Iodoacetic acid (IAA) is an emerging unregulated iodinated disinfection byproduct with high toxicity and widespread exposure. IAA has potential reproductive toxicity and could damage male reproduction. However, the underlying mechanisms and toxicological targets of IAA on male reproductive impairment are still unclear, and thus Sprague-Dawley rats and Leydig cells were used in this work to decode these pending concerns. Results showed that after IAA exposure, the histomorphology and ultrastructure of rat testes were abnormally changed, numbers of Leydig cells were reduced, the hypothalamic-pituitary-testis (HPT) axis was disordered, and testosterone biosynthesis was inhibited. Proteomics analyses displayed that oxidative stress, endoplasmic reticulum stress, and steroid hormone biosynthesis were involved in IAA-caused reproductive injury. Antioxidant enzymes were depleted, while levels of ROS, MDA, 8-OHdG, and γ-H2A.X were increased by IAA. IAA triggered oxidative stress and DNA damage, and then activated the GRP78/IRE1/XBP1s and cGAS/STING/NF-κB pathways in Leydig cells. The two signaling pathways constructed an interactive network by synergistically regulating the downstream transcription factor CHOP, which in turn directly bound to and negatively modulated steroidogenic StAR, finally refraining testosterone biosynthesis in Leydig cells. Collectively, IAA as a reproductive toxicant has anti-androgenic effects, and the GRP78/IRE1 and cGAS/STING pathway crosstalk through CHOP facilitates IAA-mediated testosterone decline.

Multiple roles of arsenic compounds in phase separation and membraneless organelles formation determine their therapeutic efficacy in tumors

Arsenic compounds are widely used for the therapeutic intervention of multiple diseases. Ancient pharmacologists discovered the medicinal utility of these highly toxic substances, and modern pharmacologists have further recognized the specific active ingredients in human diseases. In particular, Arsenic trioxide (ATO), as a main component, has therapeutic effects on various tumors (including leukemia, hepatocellular carcinoma, lung cancer, etc.). However, its toxicity limits its efficacy, and controlling the toxicity has been an important issue. Interestingly, recent evidence has pointed out the pivotal roles of arsenic compounds in phase separation and membraneless organelles formation, which may determine their toxicity and therapeutic efficacy. Here, we summarize the arsenic compounds-regulating phase separation and membraneless organelles formation. We further hypothesize their potential involvement in the therapy and toxicity of arsenic compounds, highlighting potential mechanisms underlying the clinical application of arsenic compounds.

Arsenic activated GLUT1-mTORC1/HIF-1α-PKM2 positive feedback networks promote proliferation and migration of bladder epithelial cells

Arsenic (As) is recognized as a potent environmental contaminant associated with bladder carcinogenesis. However, its molecular mechanism remains unclear. Metabolic reprogramming is one of the hallmarks of cancer and is as a central feature of malignancy. Here, we performed the study of cross-talk between the mammalian target of rapamycin complex 1 (mTORC1)/ Hypoxia-inducible factor 1 alpha (HIF-1α) pathway and aerobic glycolysis in promoting the proliferation and migration of bladder epithelial cells treated by arsenic in vivo and in vitro. We demonstrated that arsenite promoted N-methyl-N-nitrosourea (MNU)-induced tumor formation in the bladder of rats and the malignant behavior of human ureteral epithelial (SV-HUC-1) cell. We found that arsenite positively regulated the mTORC1/HIF-1α pathway through glucose transporter protein 1 (GLUT1), which involved in the malignant progression of bladder epithelial cells relying on glycolysis. In addition, pyruvate kinase M2 (PKM2) increased by arsenite reduced the protein expressions of succinate dehydrogenase (SDH) and fumarate hydratase (FH), leading to the accumulation of tumor metabolites of succinate and fumarate. Moreover, heat shock protein (HSP)90, functioning as a chaperone protein, stabilized PKM2 and thereby regulated the proliferation and aerobic glycolysis in arsenite treated SV-HUC-1 cells. Taken together, these results provide new insights into mTORC1/HIF-1α and PKM2 networks as critical molecular targets that contribute to the arsenic-induced malignant progression of bladder epithelial cells.

Arsenic exposure induced renal fibrosis via regulation of mitochondrial dynamics and the NLRP3-TGF-β1/SMAD signaling pathway

Environmental arsenic exposure is one of the major global public health problems. Studies have shown that arsenic exposure can cause renal fibrosis, but the underlying mechanism is still unclear. Integrating the in vivo and in vitro models, this study investigated the potential molecular pathways for arsenic-induced renal fibrosis. In this study, SD rats were treated with 0, 5, 25, 50, and 100 mg/L NaAsO2 for 8 weeks via drinking water, and HK2 cells were treated with different doses of NaAsO2 for 48 h. The in vivo results showed that arsenic content in the rats' kidneys increased as the dose increased. Body weight decreased and kidney coefficient increased at 100 mg/L. As a response to the elevated NaAsO2 dose, inflammatory cell infiltration, renal tubular injury, glomerular atrophy, tubulointerstitial hemorrhage, and fibrosis became more obvious indicated by HE and Masson staining. The kidney transcriptome profiles further supported the protein-protein interactions involved in NaAsO2-induced renal fibrosis. The in vivo results, in together with the in vitro experiments, have revealed that exposure to NaAsO2 disturbed mitochondrial dynamics, promoted mitophagy, activated inflammation and the TGF-β1/SMAD signaling pathway, and finally resulted in fibrosis. In summary, arsenic exposure contributed to renal fibrosis via regulating the mitochondrial dynamics and the NLRP3-TGF-β1/SMAD signaling axis. This study presented an adverse outcome pathway for the development of renal fibrosis due to arsenic exposure through drinking water.

mTORC1 - TFEB pathway was involved in sodium arsenite induced lysosomal alteration, oxidative stress and genetic damage in BEAS-2B cells

The mechanistic target of rapamycin (RAPA) complex 1 (mTORC1) - transcription factor EB (TFEB) pathway plays a crucial role in response to nutritional status, energy and environmental stress for maintaining cellular homeostasis. But there is few reports on its role in the toxic effects of arsenic exposure and the related mechanisms. Here, we show that the exposure of bronchial epithelial cells (BEAS-2B) to sodium arsenite promoted the activation of mTORC1 (p-mTORC1) and the inactivation of TFEB (p-TFEB), the number and activity of lysosomes decreased, the content of reduced glutathione (GSH) and superoxide dismutase (SOD) decreased, the content of malondialdehyde (MDA) increased, the DNA and chromosome damage elevated. Further, when mTORC1 was inhibited with RAPA, p-mTORC1 and p-TFEB down-regulated, GSH and SOD increased, MDA decreased, the DNA and chromosome damage reduced significantly, as compared with the control group. Our data revealed for the first time that mTORC1 - TFEB pathway was involved in sodium arsenite induced lysosomal alteration, oxidative stress and genetic damage in BEAS-2B cells, and it may be a potential intervention target for the toxic effects of arsenic.

Low levels of Cd2+ combined with procymidone may cause ovarian damage in mice via unfolded protein response

As no study about the combined effect of low levels of Cd2+ with procymidone (PCM) on organs and organisms, we investigated their actions on mouse-ovary in vivo and in vitro. Four-week mice were treated with corn oil for the control group, corn oil + 0.0045 mg/L Cd2+ (CdCl2 was dissolved in ultrapure water and freely consumed by mice) for Cd2+ group, 50 mg/kg/d PCM (suspended in corn oil and administered orally to mice) for PCM group, and 50 mg/kg/d PCM + 0.0015 (0.0045 and 0.0135) mg/L Cd2+ for L+ (M+ and H+) PCM group for 21 days. For in vitro experiment, the cultured ovaries were treated with acetone for the control group, 0.1% acetone + 8.4 μg/L Cd2+ for the Cd2+ group, 0.63 mg/L PCM (dissolved in acetone) for the PCM-group, and 0.63 mg/L PCM + 2.8 (8.4 and 25.2) μg/L Cd2+ for L+ (M+ and H+) PCM group for 7 days. Mouse body weight in each treatment group, the weight and volume of ovaries in all PCM groups were lower than the control. Both in vivo and in vitro, all-stage follicle numbers were lower in M+PCM and H+PCM groups, whereas the atretic follicles and CASPASE3/8 were higher; meanwhile, lower estradiol and progesterone and higher unfolded protein response (UPR) members in all PCM groups. L+, M+, and H+PCM groups had further ovarian damage and stronger UPR than PCM groups, as did M+PCM groups over Cd2+ groups. It is hypothesized low-level PCM and Cd2+ may mutually promote each other's triggered UPR and exacerbate ovarian damage.

Norcantharidin inhibits the malignant progression of cervical cancer by inducing endoplasmic reticulum stress

The antitumor effect of norcantharidin (NCTD) has been widely reported. However, whether NCTD can inhibit cervical cancer remains unknown. In the present study, it was shown that NCTD inhibited the viability of cervical cancer cells and caused cell cycle arrest in a concentration‑dependent manner. Further analysis revealed that the NCTD‑induced reduction in cell viability could be reversed by the inhibitor of apoptosis z‑VAD‑FMK and by the inhibitor of endoplasmic reticulum (ER) stress, 4‑phenylbutyric acid (4‑PBA). Additionally, NCTD led to the accumulation of reactive oxygen species as well as a decrease in the mitochondrial membrane potential in cervical cancer cells, whereas 4‑PBA pre‑treatment attenuated these alterations. In addition, NCTD increased the expression of the apoptosis‑related proteins Bip, activating transcription factor (ATF) 4 and C/EBP homologous protein in a concentration‑dependent manner. Moreover, NCTD significantly increased the expression of the ER stress‑related signaling molecules protein kinase R‑like ER kinase, inositol‑requiring enzyme 1 and ATF6, but 4‑PBA abolished these effects. In vivo experiments showed that NCTD significantly inhibited the growth of subcutaneous tumors in mice. Additionally, the expression of ER stress‑related molecules and apoptosis‑related proteins increased significantly after NCTD treatment. In conclusion, NCTD induces apoptosis by activating ER stress and ultimately curtails the progression of cervical cancer.

A Tiny Viral Protein, SARS-CoV-2-ORF7b: Functional Molecular Mechanisms

This study presents the interaction with the human host metabolism of SARS-CoV-2 ORF7b protein (43 aa), using a protein-protein interaction network analysis. After pruning, we selected from BioGRID the 51 most significant proteins among 2753 proven interactions and 1708 interactors specific to ORF7b. We used these proteins as functional seeds, and we obtained a significant network of 551 nodes via STRING. We performed topological analysis and calculated topological distributions by Cytoscape. By following a hub-and-spoke network architectural model, we were able to identify seven proteins that ranked high as hubs and an additional seven as bottlenecks. Through this interaction model, we identified significant GO-processes (5057 terms in 15 categories) induced in human metabolism by ORF7b. We discovered high statistical significance processes of dysregulated molecular cell mechanisms caused by acting ORF7b. We detected disease-related human proteins and their involvement in metabolic roles, how they relate in a distorted way to signaling and/or functional systems, in particular intra- and inter-cellular signaling systems, and the molecular mechanisms that supervise programmed cell death, with mechanisms similar to that of cancer metastasis diffusion. A cluster analysis showed 10 compact and significant functional clusters, where two of them overlap in a Giant Connected Component core of 206 total nodes. These two clusters contain most of the high-rank nodes. ORF7b acts through these two clusters, inducing most of the metabolic dysregulation. We conducted a co-regulation and transcriptional analysis by hub and bottleneck proteins. This analysis allowed us to define the transcription factors and miRNAs that control the high-ranking proteins and the dysregulated processes within the limits of the poor knowledge that these sectors still impose.

Endoplasmic reticulum stress responses and epigenetic alterations in arsenic carcinogenesis

Arsenic is a well-known human carcinogen whose environmental exposure via drinking water, food, and air impacts millions of people across the globe. Various mechanisms of arsenic carcinogenesis have been identified, ranging from damage caused by excessive production of free radicals and epigenetic alterations to the generation of cancer stem cells. A growing body of evidence supports the critical involvement of the endoplasmic stress-activated unfolded protein response (UPR) in promoting as well as suppressing cancer development/progression. Various in vitro and in vivo models have also demonstrated that arsenic induces the UPR via activation of the PERK, IRE1α, and ATF6 proteins. In this review, we discuss the mechanisms of arsenic-induced endoplasmic reticulum stress and the role of each UPR pathway in the various cancer types with a focus on the epigenetic regulation and function of the ATF6 protein. The importance of UPR in arsenic carcinogenesis and cancer stem cells is a relatively new area of research that requires additional investigations via various omics-based and computational tools. These approaches will provide interesting insights into the mechanisms of arsenic-induced cancers for prospective target identification and development of novel anti-cancer therapies.

By regulating the IP3R/GRP75/VDAC1 complex to restore mitochondrial dynamic balance, selenomethionine reduces lipopolysaccharide-induced neuronal apoptosis

Selenium (Se), as one of the essential trace elements, plays an anti-inflammatory, antioxidation, and immune-enhancing effect in the body. In addition, Se can also improve nervous system damage induced by various factors. Earlier studies have described the important role of mitochondrial dynamic imbalance in lipopolysaccharide (LPS)-induced nerve injury. The inositol 1,4,5-triphosphate receptor (IP3R)/glucose-regulated protein 75 (GRP75)/voltage-dependent anion channel 1 (VDAC1) complex is considered to be the key to regulating mitochondrial dynamics. However, it is not clear whether Selenomethionine (SeMet) has any influence on the IP3R/GRP75/VDAC1 complex. Therefore, the aim of this investigation was to determine whether SeMet can alleviate LPS-induced brain damage and to elucidate the function of the IP3R/GRP75/VDAC1 complex in it. We established SeMet and/or LPS exposure models in vivo and in vitro using laying hens and primary chicken nerve cells. We noticed that SeMet reversed endoplasmic reticulum stress (ERS) and the imbalance in mitochondrial dynamics and significantly prevented the occurrence of neuronal apoptosis. We made this finding by morphological observation of the brain tissue of laying hens and the detection of related genes such as ERS, the IP3R/GRP75/VDAC1 complex, calcium signal (Ca2+), mitochondrial dynamics, and apoptosis. Other than that, we also discovered that the IP3R/GRP75/VDAC1 complex was crucial in controlling Ca2+ transport between the endoplasmic reticulum and the mitochondrion when SeMet functions as a neuroprotective agent. In summary, our results revealed the specific mechanism by which SeMet alleviated LPS-induced neuronal apoptosis for the first time. As a consequence, SeMet has great potential in the treatment and prevention of neurological illnesses (like neurodegenerative diseases).

Chlorocholine chloride exposure induced spermatogenic dysfunction via iron overload caused by AhR/PERK axis-dependent ferritinophagy activation

Chlorocholine chloride (CCC) is a plant growth regulator used worldwide that is detectable in cereals, fruits and animal products. The health effects of CCC exposure have raised public concern. Our previous research showed that CCC exposure decreased testosterone synthesis in pubertal rats. However, little is known about whether and how pubertal CCC exposure impacts spermatogenesis. In this study, we used BALB/c mice and spermatogonia-derived GC-1 cells to examine CCC-induced spermatogenic dysfunction. In vivo, pubertal CCC exposure led to decreased testicular weight, decreased testicular germ cells and poor sperm quality. This effect worsened after cessation of CCC exposure for the next 30 days. RNA-seq and western blot analysis revealed that CCC induced aryl hydrocarbon receptor (AhR) signaling, endoplasmic reticulum stress (ERS) and ferritinophagy. Increased iron content and lipid peroxidation levels were also observed in CCC-treated testes. In vitro, it was identified that iron overload mediated by enhanced ferritinophagy occurred in CCC-treated GC-1 cells, which might be attributed to the PERK pathway in ERS. Further, for the first time, our study elucidated the involvement of AhR in CCC-induced iron overload, which aggravated testicular oxidative damage via lipid peroxidation. Considering the adverse impact of CCC exposure on rodents, supportive evidence from GC-1 cells, and the critical importance of spermatogenesis on male development, the effects of CCC on the male reproduction warrant increased attention.

Multidimensional pan-cancer analysis of HSPA5 and its validation in the prognostic value of bladder cancer

Endoplasmic reticulum (ER) stress-related genes are closely related to the occurrence, development, and immunotherapy response of tumors. This study provides a comprehensive assessment of HSPA5 from a pan-cancer perspective using multi-omics data. We analyzed the function of HSPA5 in multiple tumor types using multiple databases. Finally, immunohistochemistry was used to examine the relationship between HSPA5 expression in tissue microarrays from 100 patients with bladder cancer and the prognosis of patients with bladder cancer. Using the TCGA database, we were able to determine that HSPA5 is significantly elevated in a number of common malignancies and is linked with a bad prognosis. Cox regression analysis showed that the high expression of HSPA5 was correlated with OS, progression free survival (PFS), disease free survival (DFS), and disease special survival (DSS) of adrenocortical carcinoma (ACC). In addition, we discovered significant disparities in HSPA5 methylation and phosphorylation levels between various malignancies and normal tissues. HSPA5 expression was significantly correlated with the levels of infiltrating cells and immune checkpoint genes. HSPA5 is highly expressed in bladder cancer and patients with high HSPA5 expression have a poor prognosis. Our study provides a basis for further understanding of the role of ER stress-related gene HSPA5 in different tumor genesis and development. HSPA5 has also been shown to be a prognostic biomarker for bladder cancer patients.

Genomic and epigenetic characterization of the arsenic-induced oncogenic microRNA-21

As one of the first identified oncogenic microRNAs, the precise details concerning the transcriptional regulation and function of microRNA-21 (miR-21) are still not completely established. The miR-21 gene is situated on chromosome 17q23.2, positioned at the 3'-UTR of the gene that encodes vacuole membrane protein-1 (VMP1). In this current study, we presented evidence indicating that miR-21 possesses its own gene promoter, which can be found in the intron 10 of the VMP1 gene. Chromatin immunoprecipitation followed by global DNA sequencing (ChIP-seq) revealed the presence of a broad H3K4me3 peak spanning the entire gene body of the primary miR-21 and the existence of super-enhancer clusters in the close proximity to both the miR-21 gene promoter and the transcription termination site in arsenic (As3+)-induced cancer stem-like cells (CSCs) and human induced pluripotent stem cells (hiPSCs). In non-transformed human bronchial epithelial cells (BEAS-2B), As3+ treatment enhanced Nrf2 binding to both the host gene VMP1 of miR-21 and the miR-21 gene. Knockout of Nrf2 inhibited both the basal and As3+-induced expressions of miR-21. Furthermore, the As3+-enhanced Nrf2 peaks in ChIP-seq fully overlap with these super-enhancers enriched with H3K4me1 and H3K27ac in the miR-21 gene, suggesting that Nrf2 may coordinate with other transcription factors through the super-enhancers to regulate the expression of miR-21 in cellular response to As3+. These findings demonstrate the unique genetic and epigenetic characteristics of miR-21 and may provide insights into understanding the novel mechanisms linking environmental As3+ exposure and human cancers.

Effects of dietary arsenic exposure on liver metabolism in mice

Arsenic, a ubiquitous environmental toxicant with various forms and complex food matrix interactions, can reportedly exert differential effects on the liver compared to drinking water exposure. To examine its specific liver-related harms, we targeted the liver in C57BL/6 J mice (n=48, 8-week-old) fed with arsenic-contaminated food (30 mg/kg) for 60 days, mimicking the rice arsenic composition observed in real-world scenarios (iAsV: 7.3%, iAsIII: 72.7%, MMA: 1.0%, DMA: 19.0%). We then comprehensively evaluated liver histopathology, metabolic changes, and the potential role of the gut-liver axis using human hepatocellular carcinoma cells (HepG2) and microbiota/metabolite analyses. Rice arsenic exposure significantly altered hepatic lipid (fatty acids, glycerol lipids, phospholipids, sphingolipids) and metabolite (glutathione, thioneine, spermidine, inosine, indole-derivatives, etc.) profiles, disrupting 33 metabolic pathways (bile secretion, unsaturated fatty acid biosynthesis, glutathione metabolism, ferroptosis, etc.). Pathological examination revealed liver cell necrosis/apoptosis, further confirmed by ferroptosis induction in HepG2 cells. Gut microbiome analysis showed enrichment of pathogenic bacteria linked to liver diseases and depletion of beneficial strains. Fecal primary and secondary bile acids, short-chain fatty acids, and branched-chain amino acids were also elevated. Importantly, mediation analysis revealed significant correlations between gut microbiota, fecal metabolites, and liver metabolic alterations, suggesting fecal metabolites may mediate the impact of gut microbiota and liver metabolic disorders. Gut microbiota and its metabolites may play significant roles in arsenic-induced gut-liver injuries. Overall, our findings demonstrate that rice arsenic exposure triggers oxidative stress, disrupts liver metabolism, and induces ferroptosis.

Prenatal arsenite exposure alters maternal cardiac remodeling during late pregnancy

Exposure to inorganic arsenic through drinking water is widespread and has been linked to many chronic diseases, including cardiovascular disease. Arsenic exposure has been shown to alter hypertrophic signaling in the adult heart, as well as in utero offspring development. However, the effect of arsenic on maternal cardiac remodeling during pregnancy has not been studied. As such, there is a need to understand how environmental exposure contributes to adverse pregnancy-related cardiovascular events. This study seeks to understand the impact of trivalent inorganic arsenic exposure during gestation on maternal cardiac remodeling in late pregnancy, as well as offspring outcomes. C57BL/6 J mice were exposed to 0 (control), 100 or 1000 μg/L sodium arsenite (NaAsO2) beginning at embryonic day (E) 2.5 and continuing through E17.5. Maternal heart function and size were assessed via transthoracic echocardiography, gravimetric measurement, and histology. Transcript levels of hypertrophic markers were probed via qRT-PCR and confirmed by western blot. Offspring outcomes were assessed through echocardiography and gravimetric measurement. We found that maternal heart size was smaller and transcript levels of Esr1 (estrogen receptor alpha), Pgrmc1 (progesterone receptor membrane component 1) and Pgrmc2 (progesterone receptor membrane component 2) reduced during late pregnancy with exposure to 1000 μg/L iAs vs. non-exposed pregnant controls. Both 100 and 1000 μg/L iAs also reduced transcription of Nppa (atrial natriuretic peptide). Akt protein expression was also significantly reduced after 1000 μg/L iAs exposure in the maternal heart with no change in activating phosphorylation. This significant abrogation of maternal cardiac hypertrophy suggests that arsenic exposure during pregnancy can potentially contribute to cardiovascular disease. Taken together, our findings further underscore the importance of reducing arsenic exposure during pregnancy and indicate that more research is needed to assess the impact of arsenic and other environmental exposures on the maternal heart and adverse pregnancy events.

Immunologic Crosstalk of Endoplasmic Reticulum Stress Signaling in Bladder Cancer

Bladder cancer (BC) is a common malignant tumor of the urinary system. While current approaches involving adjuvant chemotherapy, radiotherapy, and immunotherapy have shown significant progress in BC treatment, challenges, such as recurrence and drug resistance, persist, especially in the case of muscle-invasive bladder cancer (MIBC). It is mainly due to the lack of pre-existing immune response cells in the tumor immune microenvironment. Micro-environmental changes (such as hypoxia and under-nutrition) can cause the aggregation of unfolded and misfolded proteins in the lumen, which induces endoplasmic reticulum (ER) stress. ER stress and its downstream signaling pathways are closely related to immunogenicity and tumor drug resistance. ER stress plays a pivotal role in a spectrum of processes within immune cells and the progression of BC cells, encompassing cell proliferation, autophagy, apoptosis, and resistance to therapies. Recent studies have increasingly recognized the potential of natural compounds to exhibit anti-BC properties through ER stress induction. Still, the efficacy of these natural compounds remains less than that of immune checkpoint inhibitors (ICIs). Currently, the ER stress-mediated immunogenic cell death (ICD) pathway is more encouraging, which can enhance ICI responses by mediating immune stemness. This article provides an overview of the recent developments in understanding how ER stress influences tumor immunity and its implications for BC. Targeting this pathway may soon emerge as a compelling therapeutic strategy for BC.

Intricate subcellular journey of nanoparticles to the enigmatic domains of endoplasmic reticulum

It is evident that site-specific systemic drug delivery can reduce side effects, systemic toxicity, and minimal dosage requirements predominantly by delivering drugs to particular pathological sites, cells, and even subcellular structures. The endoplasmic reticulum (ER) and associated cell organelles play a vital role in several essential cellular functions and activities, such as the synthesis of lipids, steroids, membrane-associated proteins along with intracellular transport, signaling of Ca2+, and specific response to stress. Therefore, the dysfunction of ER is correlated with numerous diseases where cancer, neurodegenerative disorders, diabetes mellitus, hepatic disorder, etc., are very common. To achieve satisfactory therapeutic results in certain diseases, it is essential to engineer delivery systems that can effectively enter the cells and target ER. Nanoparticles are highly biocompatible, contain a variety of cargos or payloads, and can be modified in a pliable manner to achieve therapeutic effectiveness at the subcellular level when delivered to specific organelles. Passive targeting drug delivery vehicles, or active targeting drug delivery systems, reduce the nonselective accumulation of drugs while reducing side effects by modifying them with small molecular compounds, antibodies, polypeptides, or isolated bio-membranes. The targeting of ER and closely associated organelles in cells using nanoparticles, however, is still unsymmetrically understood. Therefore, here we summarized the pathophysiological prospect of ER stress, involvement of ER and mitochondrial response, disease related to ER dysfunctions, essential therapeutics, and nanoenabled modulation of their delivery to optimize therapy.

The Role of microRNAs in Arsenic-Induced Human Diseases: A Review

MicroRNAs (miRNAs) are noncoding RNAs with 20-22 nucleotides, which are encoded by endogenous genes and are capable of targeting the majority of human mRNAs. Arsenic is regarded as a human carcinogen, which can lead to many adverse health effects including diabetes, skin lesions, kidney disease, neurological impairment, male reproductive injury, and cardiovascular disease (CVD) such as cardiac arrhythmias, ischemic heart failure, and endothelial dysfunction. miRNAs can act as tumor suppressors and oncogenes via directly targeting oncogenes or tumor suppressors. Recently, miRNA dysregulation was considered to be an important mechanism of arsenic-induced human diseases and a potential biomarker to predict the diseases caused by arsenic exposure. Endogenic miRNAs such as miR-21, the miR-200 family, miR-155, and the let-7 family are involved in arsenic-induced human disease by inducing translational repression or RNA degradation and influencing multiple pathways, including mTOR/Arg 1, HIF-1α/VEGF, AKT, c-Myc, MAPK, Wnt, and PI3K pathways. Additionally, exogenous miRNAs derived from plants, such as miR-34a, miR-159, miR-2911, miR-159a, miR-156c, miR-168, etc., among others, can be transported from blood to specific tissue/organ systems in vivo. These exogenous miRNAs might be critical players in the treatment of human diseases by regulating host gene expression. This review summarizes the regulatory mechanisms of miRNAs in arsenic-induced human diseases, including cancers, CVD, and other human diseases. These special miRNAs could serve as potential biomarkers in the management and treatment of human diseases linked to arsenic exposure. Finally, the protective action of exogenous miRNAs, including antitumor, anti-inflammatory, anti-CVD, antioxidant stress, and antivirus are described.

Reduced Peripheral Blood Mitochondrial DNA Copy Number as Identification Biomarker of Suspected Arsenic-Induced Liver Damage

Arsenic (As) can cause liver damage and liver cancer and is capable of seriously affecting human health. Therefore, it is important to identify biomarkers of arsenic-induced liver damage. Mitochondria are key targets of hepatotoxicity caused by arsenic. The mitochondrial DNA copy number (mtDNAcn) is the number of mitochondrial DNA (mtDNA) copies in the genome. mtDNA is vulnerable to exogenous chemical attacks, thus causing mtDNAcn to change after exposure to environmental pollutants. Therefore, mtDNAcn can serve as a potential marker to identify and assess the risk of diseases caused by exposure to environmental pollutants. In this study, we selected 272 arsenicosis patients (155 cases without liver damage and 117 cases with liver damage) and 218 participants not exposed to arsenic (155 cases without liver damage and 63 cases with liver damage) as subjects to investigate the correlation between peripheral blood mtDNAcn and arsenic-induced liver damage, as well as the ability of peripheral blood mtDNAcn to identify and assess the risk of arsenic-induced liver damage. Peripheral blood mtDNAcn in patients with arsenic-induced liver damage is significantly decreased and negatively correlated with serum ALT, AST, and GGT levels. The decrease of peripheral blood mtDNAcn was associated with an increased risk of arsenic-induced liver damage. The receiver operating characteristic (ROC) curve analysis indicated that peripheral blood mtDNAcn could specifically identify patients with liver damage in the arsenicosis group. The decision tree C5.0 model was established to identify arsenicosis in all patients with liver damage. Peripheral blood mtDNAcn was included in the model and played the most important role in the identification of arsenic-induced liver damage. This study provided a basis for the identification and evaluation of arsenic-induced liver damage by peripheral blood mtDNAcn, indicating that peripheral blood mtDNAcn is expected to be a potential biomarker of arsenic-induced liver damage, and provides clues for exploring the mechanism of arsenic-induced liver damage from mitochondria damage.

Gene expression profiles to analyze the anticancer and carcinogenic effects of arsenic in bladder cancer

OBJECTIVES

Arsenic is one of the greatest hazards as an environmental carcinogen. At the same time it is also a promising anticancer agent, that can be used to treat acute promyelocytic leukemia (APL) and some other tumors. Arsenic trioxide (ATO) exerts its therapeutic effect by promoting degradation of an oncogenic protein that drives the growth of APL cells. However, the molecular mechanisms that govern these paradoxical effects of arsenic in bladder cancer remain unclear. We speculate that they share the common mechanism that arsenic binds to the target proteins and subsequently impacts the expression of downstream genes.

METHODS

To address this issue, three Gene Set Enrichments (GSE) were loaded from the Gene Expression Omnibus (GEO) database with four expression matrices. Three of them were mice samples at exposure times of 1, 2, and 12 weeks, and the last was a human urothelial cell (HUC1) sample. Differentially expressed genes (DEGs) from 4 expression groups were identified at iDEP and analyzed at Metascape and Cytoscape for signaling pathway analysis and protein-protein interaction (PPI) analysis. The web-portals UALCAN and GEPIA were used to analyze the role of DEGs in the crosstalk between carcinogenic and anticancer effects. The putative downstream genes of arsenic binding proteins were retrieved using the Cistrome Data Browser. Real-time PCR was used to validate the expression of DEGs.

RESULTS

The signaling pathways referred to lipid metabolism. Responses to various stimuli or hormones were overrepresented in 4 expression matrices. The PPI network emphasized the role of KRAS and TNF signaling in different groups. Furthermore, BDKRB2, FOS, NR4A1, PLAU, SH3BGRL, and F10 played an important role in the crosstalk between carcinogenic and anticancer effects in bladder cancer. Arsenic may impact the activity of ACTB, BACH1, NME2, RBBP4, PARP1, and PML by direct binding, and thus influence the expression of downstream genes such as PAX6, MLLT11, LTBP1, PCSK5, ZFP36, COL8A2, and IL1R2.

CONCLUSION

Arsenic exerted carcinogenic and anticancer functions by altering the expression of crosstalk genes such as BDKRB2, FOS, NR4A1, PLAU, SH3BGRL, and F10, and these were due to arsenic binding proteins.

Identifying endoplasmic reticulum stress-related molecular subtypes and prognostic model for predicting the immune landscape and therapy response in pancreatic cancer

Endoplasmic reticulum stress (ERS) is caused by the accumulation of intracellular misfolded or unfolded proteins and is associated with cancer development. In this study, pan-cancer analysis revealed complex genetic variations, including copy number variation, methylation, and somatic mutations for ERS-related genes (ERGs) in 33 kinds of cancer. Consensus clustering divided pancreatic cancer (PC) patients from TCGA and GEO databases into two ERS-related subtypes: ERGcluster A and B. Compared with ERGcluster A, ERGcluster B had a more active ERS state and worse prognosis. Subsequently, the ERS-related prognostic model was established to quantify the ERS score for a single sample. The patient with a low ERS score had remarkably longer survival times. ssGSEA and CIBERSORT algorithms revealed that activated B cells and CD8+ T cells had higher infiltration in the low ERS score group, but higher infiltration of activated CD4+ T cells, activated dendritic cells, macrophages, and neutrophils in the high ERS score group. Drug sensitivity analysis indicated the low ERS score group had a better response to gemcitabine, paclitaxel, 5-fluorouracil, oxaliplatin, and irinotecan. RT-qPCR validated that MET, MUC16, and KRT7 in the model had higher expression levels in pancreatic tumour tissues. Single-cell analysis further revealed that MET, MUC16, and KRT7 were mainly expressed in cancer cells in PC tumour microenvironment. In all, we first constructed the ERS-related molecular subtypes and prognostic model in PC. Our research highlighted the vital role of ERS in PC and contributed to further research on molecular mechanisms and novel therapeutic strategies for PC in the future.

Knockdown of NR3C1 inhibits the proliferation and migration of clear cell renal cell carcinoma through activating endoplasmic reticulum stress-mitophagy

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is closely associated with steroid hormones and their receptors affected by lipid metabolism. Recently, there has been growing interest in the carcinogenic role of NR3C1, the sole gene responsible for encoding glucocorticoid receptor. However, the specific role of NR3C1 in ccRCC remains unclear. The present study was thus developed to explore the underlying mechanism of NR3C1's carcinogenic effects in ccRCC.

METHODS

Expression of NR3C1 was verified by various tumor databases and assessed using RT-qPCR and western blot. Stable transfected cell lines of ccRCC with NR3C1 knockdown were constructed, and a range of in vitro and in vivo experiments were performed to examine the effects of NR3C1 on ccRCC proliferation and migration. Transcriptomics and lipidomics sequencing were then conducted on ACHN cells, which were divided into control and sh-NR3C1 group. Finally, the sequencing results were validated using transmission electron microscopy, mitochondrial membrane potential assay, immunofluorescence co-localization, cell immunofluorescent staining, and Western blot. The rescue experiments were designed to investigate the relationship between endoplasmic reticulum stress (ER stress) and mitophagy in ccRCC cells after NR3C1 knockdown, as well as the regulation of their intrinsic signaling pathways.

RESULTS

The expression of NR3C1 in ccRCC cells and tissues was significantly elevated. The sh-NR3C1 group, which had lower levels of NR3C1, exhibited a lower proliferation and migration capacity of ccRCC than that of the control group (P < 0.05). Then, lipidomic and transcriptomic sequencing showed that lipid metabolism disorders, ER stress, and mitophagy genes were enriched in the sh-NR3C1 group. Finally, compared to the control group, ER stress and mitophagy were observed in the sh-NR3C1 group, while the expression of ATF6, CHOP, PINK1, and BNIP3 was also up-regulated (P < 0.05). Furthermore, Ceapin-A7, an inhibitor of ATF6, significantly down-regulated the expression of PINK1 and BNIP3 (P < 0.05), and significantly increased the proliferation and migration of ccRCC cells (P < 0.05).

CONCLUSIONS

This study confirms that knockdown of NR3C1 activates ER stress and induces mitophagy through the ATF6-PINK1/BNIP3 pathway, resulting in reduced proliferation and migration of ccRCC. These findings indicate potential novel targets for clinical treatment of ccRCC.

CL4-modified exosomes deliver lncRNA DARS-AS1 siRNA to suppress triple-negative breast cancer progression and attenuate doxorubicin resistance by inhibiting autophagy

Triple-negative breast cancer (TNBC) is a fatal disease. Drug resistance and the lack of effective drugs are the leading causes of death in patients with TNBC. Recently, long non-coding RNAs have been proven to be effective drug design targets owing to their high tissue specificity; however, an effective drug delivery system is necessary for their clinical application. In this study, we constructed a novel nanodrug delivery system based on the epidermal growth factor receptor (EGFR)-targeted aptamer CL4-modified exosomes (EXOs-CL4) for the targeted delivery of aspartyl-tRNA synthetase-antisense RNA 1 (DARS-AS1) small interfering RNA (siRNA) and doxorubicin (DOX) to TNBC cells in vitro and in vivo. This delivery system exerted potent anti-proliferation, anti-migration, and pro-apoptotic effects on TNBC cells. Silencing DARS-AS1 increased the sensitivity of TNBC cells to DOX by suppressing the transforming growth factor-β (TGF-β)/Smad3 signaling pathway-induced autophagy, thereby enhancing the synergetic antitumor effects. Collectively, our findings revealed that EXOs-CL4-mediated delivery of DARS-AS1 siRNA can be used as a new treatment strategy for DOX-resistant TNBC. Moreover, EXOs-CL4 can be used as effective drug delivery systems for targeted TNBC therapy.

Prenatal Arsenite Exposure Alters Maternal Cardiac Remodeling During Late Pregnancy

Exposure to inorganic arsenic through drinking water is widespread and has been linked to many chronic diseases, including cardiovascular disease. Arsenic exposure has been shown to alter hypertrophic signaling in the adult heart, as well as in-utero offspring development. However, the effect of arsenic on maternal cardiac remodeling during pregnancy has not been studied. As such, there is a need to understand how environmental exposure contributes to adverse pregnancy-related cardiovascular events. This study seeks to understand the impact of trivalent inorganic arsenic exposure during gestation on maternal cardiac remodeling in late pregnancy, as well as offspring outcomes. C57BL/6J mice were exposed to 0 (control), 100 or 1000 µg/L sodium arsenite (NaAsO 2 ) beginning at embryonic day (E) 2.5 and continuing through E17.5. Maternal heart function and size were assessed via transthoracic echocardiography, gravimetric measurement, and histology. Transcript levels of hypertrophic markers were probed via qRT-PCR and confirmed by western blot. Offspring outcomes were assessed through echocardiography and gravimetric measurement. We found that exposure to 1000 µg/L iAs abrogated normal physiologic growth of the maternal heart during late pregnancy and reduced transcript levels of estrogen receptor alpha (ERα), progesterone receptor membrane component 1 (Pgrmc1) and progesterone receptor membrane component 2 (Pgrmc2). Both 100 and 1000 µg/L iAs also reduced transcription of protein kinase B (Akt) and atrial natriuretic peptide (ANP). Akt protein expression was also significantly reduced after 1000 µg/L iAs exposure in the maternal heart with no change in activating phosphorylation. This significant abrogation of maternal cardiac hypertrophy suggests that arsenic exposure during pregnancy can potentially contribute to cardiovascular disease. Taken together, our findings further underscore the importance of reducing arsenic exposure during pregnancy and indicate that more research is needed to assess the impact of arsenic and other environmental exposures on the maternal heart and adverse pregnancy events.

MANF inhibits Sjögren's syndrome salivary gland epithelial cell apoptosis and antigen expression of Ro52/SSA through endoplasmic reticulum stress/autophagy pathway

BACKGROUND

Sjögren's syndrome (SS) is a typical autoimmune disease characterized by lymphocyte infiltration accompanied by the production of Ro52/SSA and La/SSB autoantibodies against whole body ribonucleoprotein particles. The release of type I IFN can induce endoplasmic reticulum stress (ERS) in submandibular gland cells. ERS not only produces a large number of Ro52/SSA antigens and changes their location, but also down-regulates autophagy and increases apoptosis.

METHOD

We collected human submandibular gland tissue samples, established an Experimental Sjögren's syndrome (ESS) mouse model, and used submandibular gland cells to test whether Mesencephalic astrocyte-derived neurotrophic factor (MANF) could reverse ERS-induced autophagy downregulation and reduce apoptosis and Ro52/SSA antigen expression.

RESULT

It was found that MANF could reduce lymphocyte infiltration and the proportion of CD4+ T cell subsets in the salivary glands, reduce the phosphorylation of AKT and mTOR proteins and the expression of ERS-related proteins, and increase the expression of autophagy proteins. We also found that MANF can reduce the expression of Ro52/SSA antigen on the cell membrane and reduce apoptosis.

CONCLUSION

In short, we found that MANF can activate autophagy, inhibit apoptosis and reduce the expression of Ro52/SSA by regulating the AKT/mTOR/LC3B signaling pathway. The above results suggest that MANF may be a protective factor against SS.

Effects of Early Life Oral Arsenic Exposure on Intestinal Tract Development and Lipid Homeostasis in Neonatal Mice: Implications for NAFLD Development

BACKGROUND

Newborns can be exposed to inorganic arsenic (iAs) through contaminated drinking water, formula, and other infant foods. Epidemiological studies have demonstrated a positive association between urinary iAs levels and the risk of developing nonalcoholic fatty liver disease (NAFLD) among U.S. adolescents and adults.

OBJECTIVES

The present study examined how oral iAs administration to neonatal mice impacts the intestinal tract, which acts as an early mediator for NAFLD.

METHODS

Neonatal mice were treated with a single dose of iAs via oral gavage. Effects on the small intestine were determined by histological examination, RNA sequencing, and biochemical analysis. Serum lipid profiling was analyzed by fast protein liquid chromatography (FPLC), and hepatosteatosis was characterized histologically and biochemically. Liver X receptor-alpha (LXR α ) knockout (L x r α - / - ) mice and liver-specific activating transcription factor 4 (ATF4)-deficient (A t f 4 Δ H e p ) mice were used to define their roles in iAs-induced effects during the neonatal stage.

RESULTS

Neonatal mice exposed to iAs via oral gavage exhibited accumulation of dietary fat in enterocytes, with higher levels of enterocyte triglycerides and free fatty acids. These mice also showed accelerated enterocyte maturation and a longer small intestine. This was accompanied by higher levels of liver-derived very low-density lipoprotein and low-density lipoprotein triglycerides, and a lower level of high-density lipoprotein cholesterol in the serum. Mice exposed during the neonatal period to oral iAs also developed hepatosteatosis. Compared with the control group, iAs-induced fat accumulation in enterocytes became more significant in neonatal L x r α - / - mice, accompanied by accelerated intestinal growth, hypertriglyceridemia, and hepatosteatosis. In contrast, regardless of enterocyte fat accumulation, hepatosteatosis was largely reduced in iAs-treated neonatal A t f 4 Δ H e p mice.

CONCLUSION

Exposure to iAs in neonatal mice resulted in excessive accumulation of fat in enterocytes, disrupting lipid homeostasis in the serum and liver, revealing the importance of the gut-liver axis and endoplasmic reticulum stress in mediating iAs-induced NAFLD at an early age. https://doi.org/10.1289/EHP12381.

Arsenic induced autophagy-dependent apoptosis in hippocampal neurons via AMPK/mTOR signaling pathway

Arsenic contamination of groundwater remains a serious public health problem worldwide. Arsenic-induced neurotoxicity receives increasing attention, however, the mechanism remains unclear. Hippocampal neuronal death is regarded as the main event of arsenic-induced cognitive dysfunction. Mitochondria lesion is closely related to cell death, however, the effects of arsenic on PGAM5-regulated mitochondrial dynamics has not been documented. Crosstalk between autophagy and apoptosis is complicated and autophagy has a dual role in the apoptosis pathways in neuronal cells. In this study, arsenic exposure resulted in mitochondrial PGAM5 activation and subsequent activation of apoptosis and AMPK-mTOR dependent autophagy. Intervention by autophagy activator Rapamycin or inhibitor 3-MA, both targeting at mTOR, accordingly induced activation or inhibition of apoptosis. Intervention by MK-3903 or dorsomorphin, activator or inhibitor of AMPK, received similar results. Our findings suggested that arsenic-induced PGAM5 activation played a role in AMPK-mTOR dependent autophagy and arsenic induced autophagy-dependent apoptosis in hippocampal neurons via AMPK/mTOR signaling pathway.

Antioxidants from different citrus peels provide protection against cancer

Cancer is one of the leading causes of death. Despite significant advancements in the discovery of medications for the treatment of cancer, these drugs are hindered by applicability and efficacy issues and frequently exhibit major side effects that can further impair patients 'quality of life. Therefore, the development of therapeutically sound anti-cancer medicines derived from natural products has gained prominence in the field of functional foods. Some of these compounds have shown efficacy in the prevention and treatment of cancer as well as low toxicity. Additionally, many recent studies have explored the recycling of agro-industrial waste to create bioactive chemicals. Citrus peels are produced in vast quantities in the food processing sector; due to their abundance of flavonoids, they may be inexpensive sources of protection against several cancers. Citrus is a common type of fruit that contains a variety of nutrients. In particular, the antioxidant chemicals found in citrus peel have been identified as potential cancer-fighting agents. Antioxidant substances such as flavonoids prevent the development of cancer by inhibiting the metastatic cascade, decreasing the mobility of cancer cells in the circulatory system, promoting apoptosis, and suppressing angiogenesis. To explore the most effective uses of citrus peel-derived antioxidants, this review presents background information, an overview of the role of citrus antioxidants in cancer therapy, and a discussion of the key underlying molecular mechanisms.

PTEN Overexpression Alters Autophagy Levels and Slows Sodium Arsenite-Induced Hepatic Stellate Cell Fibrosis

Exposure to inorganic arsenic remains a global public health problem. The liver is the main target organ, leading to arsenic-induced liver fibrosis. Phosphatase and tensin homology deleted on chromosome ten (PTEN) may participate in arsenic-induced liver fibrosis by regulating autophagy, but the exact mechanisms remain unclear. We established a mouse model of arsenic poisoning through their drinking water and a fibrosis model using the human hepatic stellate cell line LX-2 through NaAsO₂ exposure for 24 h. Masson staining measured liver fibrosis. The cells were transfected with a PTEN overexpression plasmid. Western blot and qRT-PCR determined the levels of protein/mRNA expression. Fibrosis was evident in both the mouse model and arsenic-exposed LX-2 cells. NaAsO₂ upregulated expression of autophagic markers microtubule-associated protein light chain A/B (LC3), recombinant human autophagy effector protein (Beclin-1), and hairy and enhancer of split homolog-1 (HES1), but downregulated PTEN. Alongside this, α-smooth muscle actin (α-SMA) expression was significantly upregulated by NaAsO₂. PTEN overexpression altered NaAsO₂-induced autophagy and downregulated LC3 and Beclin-1. While Notch1, HES1, α-SMA, and collagen I expression were all downregulated in the NaAsO₂ groups. Therefore, PTEN overexpression might decrease autophagy and inhibit fibrosis progression caused by arsenic, and the NOTCH1/HES1 pathway is likely involved.

Environmentally relevant doses of endocrine disrupting chemicals affect male fertility by interfering with sertoli cell glucose metabolism in mice

The growing global deterioration in several aspects of human health has been partly attributed to hazardous effects of endocrine-disrupting chemicals (EDCs) exposure. Therefore, experts and government regulatory agencies have consistently advocated for studies on the combined effects of EDCs that model human exposure to multiple environmental chemicals in real life. Here, we investigated how low concentrations of bisphenol A (BPA), and phthalates compounds affect the Sertoli cell glucose uptake/lactate production in the testis and male fertility. An EDC mixture containing a detected amount of each chemical compound in humans, called daily exposure (DE), and DE increased in magnitude by 25 (DE25), 250 (DE250), and 2500 (DE2500), and corn oil (control) were administered for six weeks to male mice. We found that DE activated estrogen receptor beta (Erβ) and glucose-regulated protein 78 (Grp 78) and disrupted the estradiol (E2) balance. In addition, DE25, DE250, and DE2500 doses of the EDC mixture via binding with Sertoli cells' estrogen receptors (ERs) inhibited the glucose uptake and lactate production processes by downregulating glucose transporters (GLUTs) and glycolytic enzymes. As a result, endoplasmic reticulum stress (ERS), marked by unfolded protein response (UPR) activation, was induced. The accompanying upregulation of activating transcription factor 4 (ATF4), inositol requiring enzyme-1 (IRE1), C/EBP homologous protein (CHOP), and mitogen-activated protein kinase (MAPK) signaling promoted antioxidant depletion, testicular cell apoptosis, abnormal regulation of the blood-testis barrier, and decreased sperm count. Therefore, these findings suggest that human and wildlife exposure to multiple environmental chemicals can produce a wide range of reproductive health complications in male mammals.

Arsenic exposure incurs hyperglycemia mediated by oxidative damage in urban adult population: A prospective cohort study with three repeated measures

The associations and potential mechanisms of low to moderate arsenic exposure with fasting plasma glucose (FPG) and type 2 diabetes mellitus (T2DM) are still unclear. To assess the effects of short-term and long-term arsenic exposure on hyperglycemia and the mediating effect of oxidative damage on such association, three repeated-measures studies with 9938 observations were conducted in the Wuhan-Zhuhai cohort. The levels of urinary total arsenic, FPG, urinary 8-iso-prostaglandin F2alpha (8-iso-PGF2α), urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), and plasma protein carbonyls (PCO) were measured. Generalized linear mixed models were used to evaluate the exposure-response relationships of urinary total arsenic with FPG and the prevalent risks of impaired fasting glucose (IFG), T2DM, and abnormal glucose regulation (AGR). Cox regression models were applied to assess the associations of arsenic exposure with incident risks of IFG, T2DM, and AGR. Mediation analyses were performed to assess the mediating effects of 8-iso-PGF2α, 8-OHdG, and PCO. In cross-sectional analyses, each one-unit increase in natural log-transformed urinary total arsenic was associated with a 0.082 (95% CI: 0.047 to 0.118) mmol/L increase in FPG, as well as a 10.3% (95% CI: 1.4%-20.0%), 4.4% (95% CI: 5.3%-15.2%), and 8.7% (95% CI: 1.2%-16.6%) increase in prevalent risks of IFG, T2DM, and AGR, respectively. In longitudinal analyses, arsenic exposure was further associated with the annual increased rate of FPG with a β (95% CI) of 0.021 (95% CI: 0.010 to 0.033). The incident risks of IFG, T2DM, and AGR were increased without statistical significance when arsenic levels increased. Mediation analyses showed that 8-iso-PGF2α and PCO mediated 30.04% and 10.02% of the urinary total arsenic-associated FPG elevation, respectively. Our study indicated that arsenic exposure was associated with elevated level and progression rate of FPG among general Chinese adults, where lipid peroxidation and oxidative protein damage might be the potential mechanisms.

Long-term exposure to arsenic in drinking water leads to myocardial damage by oxidative stress and reduction in NO

Chronic arsenic exposure causes myocardial damage. The aim of this study is to investigate if oxidative stress and reduction in NO is involved in the myocardial damage induced by arsenic in drinking water. Rats were divided into a control group and different doses of sodium arsenite. With increasing sodium arsenite concentrations in drinking water, localised inflammatory foci and necrotic myocardial tissues were gradually observed. Compared to the control group, the activities and gene expression of antioxidant enzymes in arsenic-exposed rats decreased. NO content and the NOS activity as well as the expression of NOS mRNA in the myocardial tissue of exposed rats, decreased, and the extracellular NO content of cardiomyocytes treated with sodium arsenite also decreased. The rate of cell apoptosis induced by sodium arsenite decreased after treatment with sodium nitroprusside (an NO donor). In conclusion, arsenic exposure in drinking water can lead to myocardial injury and cardiomyocyte apoptosis through oxidative stress and a reduction in NO content.

Modulatory Role of Autophagy in Metformin Therapeutic Activity toward Doxorubicin-Induced Nephrotoxicity

Doxorubicin (DOX) is a frequent chemotherapeutic drug used to treat various malignant tumors. One of the key factors that diminish its therapeutic importance is DOX-induced nephrotoxicity. The first-line oral antidiabetic drug is metformin (Met), which also has antioxidant properties. The purpose of our study was to investigate the underlying molecular mechanisms for the potential protective effects of Met on DOX-triggered nephrotoxicity. Four animal groups were assigned as follows; animals received vehicle (control group), 200 mg/kg Met (Met group), DOX 15 mg/kg DOX (DOX group), and a combination of DOX and Met (DOX/Met group). Our results demonstrated that DOX administration caused marked histological alterations of widespread inflammation and tubular degeneration. Notably, the DOX-induced dramatic up-regulation of the nuclear factor-kappa B/P65 (NF-κB/P65), microtubule-associated protein light chain 3B (LC3B), neutrophil gelatinase-associated lipocalin (NGAL), interleukin-1beta (IL-1β), 8-hydroxy-2' -deoxyguanosine (8-OHdG), and Beclin-1 in renal tissue. A marked increase in the malondialdehyde (MDA) tissue level and a decrease in the total antioxidant capacity (TAC) were also recorded in DOX-exposed animals. Interestingly, Met could minimize all histopathological changes as well as the disruptions caused by DOX in the aforementioned measures. Thus, Met provided a workable method for suppressing the nephrotoxicity that occurred during the DOX regimen via the deactivation of the Beclin-1/LC3B pathway.

AAZ2 induces mitochondrial-dependent apoptosis by targeting PDK1 in gastric cancer

Drastic surges in intracellular reactive oxygen species (ROS) induce cell apoptosis, while most chemotherapy drugs lead to the accumulation of ROS. Here, we constructed an organic compound, arsenical N-‍(4-(1,3,2-dithiarsinan-2-yl)phenyl)acrylamide (AAZ2), which could prompt the ROS to trigger mitochondrial-dependent apoptosis in gastric cancer (GC). Mechanistically, by targeting pyruvate dehydrogenase kinase 1 (PDK1), AAZ2 caused metabolism alteration and the imbalance of redox homeostasis, followed by the inhibition of phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway and leading to the activation of B-cell lymphoma 2 (Bcl2)/Bcl2-associated X (Bax)/caspase-9 (Cas9)/Cas3 cascades. Importantly, our in vivo data demonstrated that AAZ2 could inhibit the growth of GC xenograft. Overall, our data suggested that AAZ2 could contribute to metabolic abnormalities, leading to mitochondrial-dependent apoptosis by targeting PDK1 in GC.

The protective effect of natural or chemical compounds against arsenic-induced neurotoxicity: Cellular and molecular mechanisms

Arsenic is a notorious metalloid that exists in the earth's crust and is considered toxic for humans and the environment. Both cancerous and non-cancerous complications are possible after arsenic exposure. Target organs include the liver, lungs, kidney, heart, and brain. Arsenic-induced neurotoxicity, the main focus of our study, can occur in central and peripheral nervous systems. Symptoms can develop in a few hours, weeks, or years depending on the quantity of arsenic and the duration of exposure. In this review, we aimed to gather all the compounds, natural and chemical, that have been studied as protective agents in cellular, animal, and human reports. Oxidative stress, apoptosis, and inflammation are frequently described as destructive mechanisms in heavy metal toxicity. Moreover, reduced activity of acetylcholinesterase, the altered release of monoamine neurotransmitters, down-regulation of N-methyl-D-aspartate receptors, and decreased brain-derived neurotrophic factor are important underlying mechanisms of arsenic-induced neurotoxicity. As for neuroprotection, though some compounds have yet limited data, there are others, such as curcumin, resveratrol, taurine, or melatonin which have been studied more deeply and might be closer to a reliable protective agent. We collected the available information on all protective agents and the mechanisms by which they fight against arsenic-induced neurotoxicity.